---
title: "Trimethyl benzene (all isomers and mixed compounds) (25551-…"
url: https://analyt-mtc.com/tools/hazard-search/trimethyl-benzene-all-isomers-and-mixed-compounds-25551-13-7/
lang: en
alternates:
  en: https://analyt-mtc.com/tools/hazard-search/trimethyl-benzene-all-isomers-and-mixed-compounds-25551-13-7/
  de: https://analyt-mtc.com/de/tools/gefahrstoffsuche/trimethyl-benzene-all-isomers-and-mixed-compounds-25551-13-7/
---

Hazard search

# Trimethyl benzene (all isomers and mixed compounds)

CAS number

25551-13-7

Also known as

1,2,3-Trimethylbenzene (see online Passive Sampling Guide) · 1,2,4-Trimethylbenzene · Methylxylene · Trimethylbenzene · Trimethylbenzenes (all isomers or mixtures)

## UK workplace exposure limits

| Limit | Value | Applies to |
| --- | --- | --- |
| 8-hour TWA | 25 ppm |  |
| 8-hour TWA | 125 mg/m³ |  |

## Sampling methods

| Method | Sampling | Medium | Analysis | Part numbers |
| --- | --- | --- | --- | --- |
| **MDHS 72** / VOCs by thermal desorption and GC / [Method document (opens in a new tab)](https://www.hse.gov.uk/pubns/mdhs/pdfs/mdhs72.pdf) | Active (pump) | Tenax thermal desorption tube (250mg) or Chromosorb 106 TD tube (300mg) | TD, GC | [226-357](https://analyt-mtc.com/catalog/product/skc-tenax-sorbent-tubes/#part-226-357) / [226-358](https://analyt-mtc.com/catalog/product/skc-chromosorb-sorbent-tubes/#part-226-358) |
| **MDHS 80** | Active (pump) |  | TD, GC | [226-357](https://analyt-mtc.com/catalog/product/skc-tenax-sorbent-tubes/#part-226-357) |
| **MDHS 88** / VOCs by solvent desorption and GC / [Method document (opens in a new tab)](https://www.hse.gov.uk/pubns/mdhs/pdfs/mdhs88.pdf) | Passive | Passive sampler | GC-FID | [575-001](https://analyt-mtc.com/catalog/product/skc-organic-vapour-passive-samplers/#part-575-001) / [575-002](https://analyt-mtc.com/catalog/product/skc-organic-vapour-passive-samplers/#part-575-002) |
| **MDHS 104** / VOCs by solvent or thermal desorption and GC / [Method document (opens in a new tab)](https://www.hse.gov.uk/pubns/mdhs/pdfs/mdhs104.pdf) | Active (pump) | Tenax (250mg) or Chromosorb 106 (300mg) thermal desorption tube |  | [226-357](https://analyt-mtc.com/catalog/product/skc-tenax-sorbent-tubes/#part-226-357) / [226-358](https://analyt-mtc.com/catalog/product/skc-chromosorb-sorbent-tubes/#part-226-358) |
| **MDHS 104** / VOCs by solvent or thermal desorption and GC / [Method document (opens in a new tab)](https://www.hse.gov.uk/pubns/mdhs/pdfs/mdhs104.pdf) | Active (pump) | Tenax TD tube (250mg) |  | [226-357](https://analyt-mtc.com/catalog/product/skc-tenax-sorbent-tubes/#part-226-357) |
| **OSHA 5000** / Organic Vapour Sampling Group 1 by GC-FID / [Method document (opens in a new tab)](https://www.osha.gov/sites/default/files/methods/5000.pdf) | Active (pump) | Anasorb CSC sorbent tube |  | [226-01](https://analyt-mtc.com/catalog/product/skc-anasorb-sorbent-tubes/) |
| **OSHA PV2091** / Trimethylbenzenes by GC-FID / [Method document (opens in a new tab)](https://www.osha.gov/sites/default/files/methods/osha-pv2091.pdf) | Active (pump) | Charcoal tube (100/50mg) |  | [226-01](https://analyt-mtc.com/catalog/product/skc-anasorb-sorbent-tubes/) |
| **EPA TO-17** | Active (pump) |  | TD, GC | [226-350](https://analyt-mtc.com/catalog/product/skc-anasorb-sorbent-tubes/#part-226-350) / [226-347](https://analyt-mtc.com/catalog/product/skc-anasorb-sorbent-tubes/#part-226-347) / [224-26-02](https://analyt-mtc.com/catalog/product/skc-gas-and-vapour-sampling-accessories/#part-224-26-02) / [224-26-CPC](https://analyt-mtc.com/catalog/product/skc-gas-and-vapour-sampling-accessories/#part-224-26-cpc) |
| **EPA TO-17** / Toxic Organic Compounds by thermal desorption and GC / [Method document (opens in a new tab)](http://www.epa.gov/ttn/amtic/files/ambient/airtox/to-17r.pdf) | Active (pump) | Thermal desorption tube |  | [226-300](https://analyt-mtc.com/catalog/product/skc-thermal-desorption-sorbent-tubes/#part-226-300) |
| **Other** | Passive |  |  | [575-001](https://analyt-mtc.com/catalog/product/skc-organic-vapour-passive-samplers/#part-575-001) |
| **Other Internal** | Passive |  | TD, GC | [690-101](https://analyt-mtc.com/catalog/product/skc-ultra-passive-samplers/#part-690-101) / [690-103](https://analyt-mtc.com/catalog/product/skc-ultra-passive-samplers/#part-690-103) / [690-104](https://analyt-mtc.com/catalog/product/skc-ultra-passive-samplers/#part-690-104) |
| **Other Internal** | Passive |  | GC-FID | [690-105](https://analyt-mtc.com/catalog/product/skc-ultra-passive-samplers/#part-690-105) |

Methods and limits as published by their agencies and summarised by SKC; check the current method and the limit that applies to you before sampling.

Source: [SKC Ltd (UK), Hazard Search, used with SKC's permission (opens in a new tab)](https://www.skcltd.com/hazard-search.html); [SKC Inc. (USA), Sampling Guides, used with SKC's permission (opens in a new tab)](https://international.skcinc.com/sampling-guides/)